Do you know are they working on more specifically like from a news report? They made something about Dudley Do Right, but it only came out on home video. There was a Popeye movie that Sony was making but that apparently got cancelled.
Wikipedia says Dreamworks bought the rights for a bunch of characters for millions of dollars (
DreamWorks Classics - Wikipedia So I wouldn't be surprised if Universal doesn't change much of Toon Lagoon now that I learned that. They could just build something in a park near the Convention Center, but that would be more expensive than just building something to do with Nintendo there. They could maybe have something like the gondola idea connecting that new park to the Nintendo area in the original park possibly in addition to one or more areas like Wet N Wild.
I guess it might be hard to do something that has the equivalent effect of the history and familiarity people will have built up with what is already in Toon Lagoon and it is a very large variety of characters there that would be replaced. With that much variety, that is a lot of things that people might like or dislike. So, at least that increases the possibility of people likeing something there.